With each season there are changes in day length, wind speed and direction, temperature, and rainfall, which dictate the optimal times for plants and animals to initiate growth, development, and reproduction. Plants are sessile and cannot escape or hide from seasonal change. Getting the timing right so that germination, bud burst, flowering, dormancy, and other critical processes are aligned with seasonal changes is essential for survival. Animals have more choices. They can migrate, hibernate, or, like plants, adapt their physiology and behaviour to cope with the changes. ‘Seasons of life’ explains that the most stable indicator of the time of year is photoperiod (day length) and considers the different light-detecting mechanisms in plants and animals.